Nitrile O-Rings & Gaskets | Seal & Design Inc.

Nitrile (NBR)

Nitrile MaterialNitrile rubber is the general term for acrylonitrile butadiene terpolymer. The acrylonitrile content of nitrile sealing compounds varies considerably (18% to 50%) and influences the physical properties of the finished material.

The higher the acrylonitrile content, the better the resistance to oil and fuel. At the same time, elasticity and resistance to compression set is adversely affected. In view of these opposing realities, a compromise is often drawn, and a medium acrylonitrile content selected. Nitrile has good mechanical properties when compared with other elastomers and high wear resistance.

Both o-rings and gaskets can be made from Nitrile materials.

Names: Acrylonitrile-Butadienne, NBR, Buna-N, Nitrile

Compound Info
ASTM D1418 Designation NBR
ASTM D2000/SAE J200 Type, Class BF, BG, BK, CH
Hardness (Shore A) 40-90
Color black
Thermal Properties
Standard Min Temp. -40°F (-40°C)
Max Temp. 250°F (121°C)


Chemical Resistance
Chemical Resistance
  • Aliphatic hydrocarbons (propane, butane, petroleum oil, mineral oil and grease, diesel fuel, fuel oils) vegetable and mineral oils and greases
  • HFA, HFB, and HFC fluids
  • Dilute acids, alkali and salt solutions at low temps.
  • Water (special compounds up to 212°F (100°C)
Not compatible
NOT compatible
  • Fuels of high aromatic content (for flex fuels a special compound must be used)
  • Aromatic hydrocarbons (benzene)
  • Chlorinated hydrocarbons (trichloroethylene)
  • Polar solvents (ketones, esters, ethers, acetones)
  • Strong acids
  • Glycol based brake fluids
  • Ozone, weather, and atmospheric aging

Disclaimer: These are general guidelines only. All materials should be tested in your application.